Cleanup: remove flow-graph's cached copy of num stack locals as it can become stale if variables ge…

runtime/vm/flow_graph.h

Index: runtime/vm/flow_graph.h
===================================================================
--- runtime/vm/flow_graph.h	(revision 41789)
+++ runtime/vm/flow_graph.h	(working copy)
@@ -99,10 +99,10 @@
     return num_copied_params_ + num_non_copied_params_;
   }
   intptr_t variable_count() const {
-    return parameter_count() + num_stack_locals_;
+    return parameter_count() + num_stack_locals();
   }
   intptr_t num_stack_locals() const {
-    return num_stack_locals_;
+    return parsed_function().num_stack_locals();
   }
   intptr_t num_copied_params() const {
     return num_copied_params_;
@@ -339,7 +339,6 @@
   ParsedFunction& parsed_function_;
   const intptr_t num_copied_params_;
   const intptr_t num_non_copied_params_;
-  const intptr_t num_stack_locals_;
   GraphEntryInstr* graph_entry_;
   GrowableArray<BlockEntryInstr*> preorder_;
   GrowableArray<BlockEntryInstr*> postorder_;